1. Field of the Invention
The present invention relates to an image display device, more particularly to an optical head-mounted display for projecting image onto pupils of human eyes.
2. Description of Related Art
Nowadays, LCD panels are widely used to the portable devices, such as smart phones, tablet computers, handheld video game devices . . . etc. Thus, people can enjoy different kinds of entertainments from these portable devices in the leisure time. However, to watch the video or movie on these portable devices for several hours often causes people to feel uncomfortable, especially on their necks and hands.
In order to improve the shortcoming mentioned above, a manufacturer designs one image display device which is worn on a user's head. The image display device uses a mapping device to show the image in front of the user's eyes. Thus, the user can comfortably enjoy the video or movie via the image display device.
Unfortunately, the image display device still has one shortcoming. The users cannot be aware of the traffic around themselves when they wear the image display to go on the road because the image mapped from the image display device occupies the user's eyes and the view around the user cannot be transparent into the user's eyes. Although some manufacturers try to use beam splitters or light guide devices to overcome this shortcoming, the image becomes ambiguous because of the energy loss of photons.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional.